hobbs



Patented Nov. l, I898.

D. D. HOBBS.

GAS ENGINE.

(Application filed Nov. 16, 1896.)

4 Sheets Shaet I.

(N0 Model.)

No. 6l3,4l7. Patented Nov. l, I898. D. D. HOBBS.

GAS ENGINE (Application filed Nov. 16, 1896.) &No Model.) 4 Sheets-Sheet 2.

in) enTo/ EYERS no. PHOTD-LlTND-.WKSNINOYON u c No. 68,417.. Patented Nov. 1, I898. D. D. HOBBS.

GAS ENGINE.

(Application flied Nov. 16, 1596.

\No Model.) 4 Sheets-Sheet 3.

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DAVIS D. HOBBS, OF CLEVELAND, OHIO, ASSIGNOR TO THE MONARCH DUPLEX ENGINE COMPANY.

GAS-ENGINE.

SPECIFICATION formingpart of Letters Patent No. 613,417, dated November 1, 1898.

Applieationfiled November 16,1896- Serial No. 612,350. (No model.)

To all whom it may concern;

Be it known that I, DAVIS D. HOBBS, a citizen of the United States, residing at Cleve land, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Gas Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The engine herein shown and described is provided with means to use oil as the source of its power, and hence in that sense is a vapor-engine; but I may use either manufactured or natural gas, and its principle of construction is that of the gas-engine. It will also be seen that the engine is equipped with a single double-acting vibrating piston arranged to .take explosions on both sides and that the necessary mechanism is in duplicate to enable this to be done, and, finally, though the engine itself is non-reversible it is made reversible in effect or operation, as hereinafter fully described.

In the accompanying drawings, Figure 1 is a vertical sectional side elevation of the engine on a line corresponding to 1 1 of Fig. 2. Fig. 2 is a horizontal sectional plan on line 2 2, Fig. 1. Fig. 3 is a cross-section of the engine on line 3 3, Fig. 2. Fig. 4 is a crosssection of the engine on line4 4, Fig. 2. Fig. 5 is an enlarged sectional front elevation of the valve-reversing mechanism. Fig. 6 is an enlarged front elevation of said valve-reversing mechanism.

A represents the bed and framework of the engine, shown here as having an oil-reservoir a, from which the oil is pumped by pumps B to the carbureter and mixing-chamber G. The carburetor and mixing-chamber, so called, as shown, is a short pipe C, open at its outer end to admit air and in open communication at its inner end with the inletpassage 8. At each stroke of the pump a sufficient quantity of the oil (preferably gasolene) is delivered into this pipe through the pipe 3,and,being vaporized,the vapor is mixed with the air as both pass through a fine-wire gauze c, which extends across pipe 0. The

particular form of carburetor is not an essential part of the invention, and any other device for vaporizing the gasolene and mixing the vapor with the air may be employed. If gas were used, the pumps would not be required, nor would they be required if a gravityfeed were available. In this case they are operated by cams d 01 upon the valve-shaft D; but they may have any suitable connection.

Referring particularly to Fig. 1, it will be seen that the engine contains a segmental piston-chamber 1, the ends of said chamber being extended vertically to form what may be called the explosion-chambers. 1 1 The shaft F extends across this piston-chamber, being placed axially with respect thereto. It is journaled in the sidewalls of this segmental piston chamber and extends entirely through one of said walls, whereby power may be taken from the shaft, as hereinafter set forth. The single piston E is keyed or otherwise rigidly secured to the shaft F, and it nicely fits the segmental piston-chamber, in which it vibrates, through an arc of ninety degrees, from a position near one end of said chamber to a point near to the other end thereof, as indicated by the dotted lines in Fig. 1. A horizontal inlet-passage 8 connects the two explosion chambers 1 1, said inlet-passage being, as before stated, in

open communication with the carbureter. A

similar exhaust-passage 9 connects said explosion-chambers, these two passages bein side by side and separated by a partition a through which a valve-shaft D passes. Suitable valves are provided whereby the communication between the explosion-chambers 1 1 (which form the ends of the piston-chambers) and the exhaust and inlet passages, respectively,may be established or discontinued in the proper sequence and at the proper times. It is not material to the broad invention herein disclosed and claimed how these valves may be constructed or by what mechanism they shall be operated. The desired results may, however, be obtained by means of the disk valves 6 and 7, secured to the valve-shaft D, within the explosion-chambers '1 1 over the ends of said two passages. Each valve has an opening 7', which as the valveshaft revolves will register at the proper times with the inlet and outlet passages 8 and 9. This valve-shaft is driven from the shaft F through suitable mechanism, which will be presently described, so that it will make one complete revolution during the time the shaft F is making two complete backward and forward movements, which movements are necessary to complete each cycle of the engine. Each of these valve-disks is secured to the valve-shaft in such manner and the opening 7 thereon is of such size relative to the disk itself that when the piston at the beginning of its cycle relative to the corresponding end of the piston-chamber begins to move forward-that is to say, away from said end-the opening 7 comes into line with the inlet-passage and opens communication between said passage and the said end of the piston-chamberthat is to say, the corresponding explosion-chamberand this communication is maintained until the piston completes the described forward movement. Just as the piston begins its first return movement the opening 7 passes the inlet-passage, and therefore the communication between the inlet-passage and said end of the pistonchamber is closed, and it remains closed during the time when the said piston is' making its first return movement toward and its second forward movement from said end of the piston-chamber. Just as the piston begins its second return movement the opening 7 comes into line with the exhaust-passage, and the communication between said exhaustpassage and the end of the piston-chamber under consideration is established and maintained until this second return movement is completed. This completes the cycle of the engine at one end of the piston chamber. The valve-disk at the other end of the pistonchamber moves in like manner and with like results, except that neither the inlet-passage nor the outlet-passage is placed in communication with both ends of the piston-chamber at the same time.

The result of operating the valves in the described sequence and relation to the movement of the piston is that when the piston is making its first forward movement from one end of the piston-chamber the explosive mixture is drawn into said end of said chamber. During its first return stroke the charge so drawn in is compressed, and then at the end of this movement the compressed charge is exploded, whereupon the piston makes its second forward movement as the result of this explosion. As the piston is making its second return stroke the exploded charge is expelled through the exhaust-passage. A similar sequence of events occurs in the other end of the piston-chamber at the same time, but in the following relation to the events last described: lVhen the charge is being taken in at, say, the right end of the piston-chamber, the exploded charge is being expelled from the left end. lVhen the charge is being compressed in the right end, it is being drawn into the left end. Vhen the explosion takes place in the right end, the charge is being compressed in the left end. When the exploded charge is being expelled from the right end, the charge is exploded in the left end, these operations being repeated in the described sequence and relation to each other indefinitely. Itwill be understood that since the explosions take place in both ends of the piston-chamber the piston is positively driven in both directions.

The compressed charges in the ends of the piston chambers are exploded by electric sparks produced by the contact of the fingers d on the valve-shaft D with the electric sparking fingers c in the explosion-chambers, although any means may be employed to produce the said explosions. In the engine, as shown, one of these explosions occurs during each half of one revolution of the engine-shaft K, which revolution is followed by one complete revolution during which there is no explosion. The shaft F is carried through its idle movementsthat is to say, the movements which are not impelled by the explosion on one side or the other of the piston by a fly-wheel G on the shaft K.

In the foregoing description there is no provision for the reversal of the engine or any of its parts and no reversal whatever occurs; but I do provide for reversal in the power connections, so that the power of the engine may be utilized in reversed positions, if de sired. Thus following the parts as we leave crank-pin f on shaft F, Fig. 2, we have a power-shaft K, driven from shaft F by connecting-rod L and carrying a wheel G or other means for taking oif power. It frequently occurs that a reversible gas-engine is wanted for one use or anotheras, for example, in the running of yachts or other light craft.

My invention has in view the production of an engine which will accommodate travel back or forth, as may be desired, with equal facility, whereby a boat can be propelled or backed at pleasure. To this end I employ the mechanism shown in Figs. 5 and 6. Here it will be seen that there are two free bevel or miter wheels 0 and P on shaft K facing each other and engaging the bevel-driven gear R on the short driven shaft S, which has a pinion T meshing with gear V on valve-shaft D and serving to drive the same. The power to operate the valve-shaft is thus taken off the drive-shaft K, and since both gears O and P are constantly in mesh with gear B only one can be in action at a time and the other must run idle. Vhich gear is in mesh depends on the direction of rotation of shaft K, and the moment this direction is changed or reversed the then-engaged gear 0 or P will be disengaged also and the other one will come into action. To effect these changes automatically upon each reversal of shaft K, I employ a key 20, adapted to slide in a spline or channel in shaft K and of such length as to play operatively between the cams 22 and 2t on the said gear-wheels O and P, respectively. A collar 25 serves to confine key 20 in its groove, and both gears and their cams are alike. That gear is for the time in action which has its cam engaged by the key 20, and since said wheels are arranged as shown and rotate in opposite directions it follows that if either wheel be locked to rotate with shaft K it will continue to rotate the gear R and its shaft 8 in the same direction as before, and this is the object of this mechanism, which gives me the effect, practically, of a reversible engine. The engagements and disengagements between key 20 and cams 22 24 are automatic and certain, and the shaft cannot turn more than half-way around before it will be engaged by the key 20 if the other cam is released by reversal of the drive-shaft.

The foregoing description shows the connection of this reversing mechanism with a gas-engine; but it may be employed in other connections and uses without departing from the spirit of the invention.

When reversal of the engine is to be accomplished, the engine is stopped, as necessarily occurs in all engines, and the shaft K is rotated and started in the reverse direction, either by an automatic starter or by hand.

-As this occurs the spiral cam corresponding to the direction of rotation becomes engaged with the key 20 and locks its gear-wheel therewith. It will be seen that-both cams are perfect spirals and that their edges are parallel all the way around and are so arranged as to sustain exactly similar relations to the key 20. Hence when disengagement occurs with either cam that cam at once operates to make engagement through the other and to maintain such engagement. Having described my invention, I claim 1. In an explosion-engine, in combination, a casing containing a segmental piston-chamber and two explosion-chambers which are respectively in open communication with opposite ends of said piston-chamber, an inlet-passage and an outlet-passage, both formed in the casing, the ends of said passages being respectively connected with the two explosionchambers, valves for closing the communication between said passages and chambers, electric spark-producing devices in said explosion-chambers, a rotating shaft, and mechanism whereby said shaft operates said valves and spark-producing devices, an oscillating shaft mounted axially with respect to the pis-v ton-chamber, piston -wings secured to said shaft and fitted to said chamber, and mechanical connections between the oscillating shaft and the rotating shaft, substantially asand for the purpose specified.

2. In an explosion-engine, in combination, a segmental piston-chamber, an inlet and an outlet passage above said piston-chamber and communicating with both ends thereof, a partition separating said passages, a single rotating valve-shaft journaled in said partition and valves secured to opposite ends thereof carried thereby for controlling said passages, and a single oscillating piston in said'chamber, substantially as described.

3. In a gas-engine, in combination, a reversible power-shaft, a valve-operating shaft, and a set of interchangeable Wheels and cams connecting said shafts whereby the same direction of rotation of the valve-shaft is maintained when the power-shaft revolves in either direction, substantially as described.

4. In a gas-engine, in combination, a valveoperating shaft, a power-shaft, and interchangeable gears connecting said shafts, having each a spiral cam on its side, and'a key in the power-shaft between said cams, substantially as described.

5. In a gas-engine, in combination, a powershaft and a valve-operating shaft, gears connecting said shafts, and means between said gears constructed to automatically lock on one and unlock on the other when the power= shaft is reversed, substantially as described.

6. In a gas-engine, in combination, a valveoperating shaft having a single gear, a power= shaft, two bevel-gears loosely mounted there= on and meshing with the gear on the valve= operating shaft, spiral cams on said gears, and a key engaging with the power-shaft between said gears to automatically lock one or the other to said power-shaft, substantially as described.

7. In a gas-engine, in combination, a pistonchamber, valves therefor, a valveoperating shaft, the power-shaft, a pair of bevel-gears loosely mounted thereon, spiral cams on each of said bevel*gears,a movable keyin the power= shaft in position to be engaged by either of said cams and moved into engagement withthe other gear, a bevel-gear meshing with said two gears, and mechanism transmitting motion from the last-named bevel-gear to the valve-operating shaft, substantially as described.

8. In a gas-engine, in combination, a pistonch'amber, an oscillating piston therein, a gas inlet and exhaust at each end of the pistonchamber, a single rotating valve for each set of inlet and exhaust openings, a shaft on which said valves are secured, a reversible powershaft, a shaft intermediate of said powershaft, a valve-shaft, a gear and cam mechanism connecting the power-shaft and intermediate shafts, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

DAVIS D. HOBBS.

WVitnesses:

E. L. THURSTON, E. B. GILOHBIST. 

